20　ibid.
21　O Pickup (2 February 2018) What happens inside Rolls-Royce R2 Data Labs?
22　E Biba (14 February 2017) The jet engine with 'digital twins'.
23　ibid.
10. 实验
1　I Rodà (November/December 2016) Aqueducts: Quenching Rome's thirst.
2　D Szondy (24 January 2018) Falcon heavy vs. the classic Saturn V.
3　ibid.
4　T Fernholz (21 February 2017) SpaceX's self-landing rocket is a flying robot that's great at math.